Dr. Allen Knutson, AgriLife Extension entomologist, said spring is a good time to control fire ants as this is when they search for food and build mounds, which makes them easier to locate.
Broadcast baits are the core of AgriLife Extension’s recommended treatment. The method becomes effective as temperatures begin to rise and ants begin to gather forage to feed their new brood, he said. But once hot, dry summer conditions set in, fire ants become less active and mounds become less visible as ants go deeper in search of moisture.
It’s a good time to apply baits in spring as they are generally slow acting. It typically takes two to four weeks to see results from using baits containing indoxacarb, spinosad or hydramethylnon. Starting as early as possible provides more time to enjoy summer without fire ants.
Knutson said baits with other active ingredients may require two to six months to achieve results, but often require fewer retreatments. So again, starting early has benefits.
AgriLife Extension developed the Two Step methods of fire ant control to help consumers make sense of all the products on the market, Merchant said.
Users should read the pesticide label to be sure the site they are treating is listed on the product label.
The first step in the Two-Step Method is application of a fire ant bait to the treatment area, Knutson said. Baits have the advantage in that users don’t have to find each fire ant colony and treat them directly. They are also are less costly in terms of time and amount of product needed when treating a large area.
For those fire ant colonies in high traffic areas, such as around a mailbox, that must be controlled quickly, follow Step 2 and treat these mounds individually with a contact insecticide.
Baits do have a limited shelf life, Merchant said. He advises users to discard bait products opened for more than a few months. Users should also make sure products they purchase from stores are not more than two years beyond their production date. If users are not sure of the age of the bait, apply the product around an active fire ant mound. If ants gather the bait and take it underground within a few minutes, it should be fresh and ready to use, he said.
“Many native ant species are beneficial in that they compete for food with fire ants, and some also attack new fire ant queens as they attempt to start a new colony,” Knutson said. “Insecticides for fire ants also kill native ants, thus only use these insecticides if fire ants are present.”
Lonnie Jenschke is an Erath County extension agent.